Approx. 27 years i really hope this helped!!
Answer:
Independent variable: Adding/not adding soil.
Dependent variables: Does the plant grow? Amount of leaves, plant length.
Controlled variables: Type of plant used, amount of sunlight received, pot used for plant, amount of water given, temperature of soil, etc.
Explanation:
Independent variable: The thing that you want to change. To see if plants need soil to grow, you would need to either add or remove soil altogether.
Dependent variables: The thing that is being measured. By adding your independent variable, you should be able to answer certain questions.
Controlled variables: Things you want to keep the same for each experimental group. For example, if you used different plants, your results could be affected negatively as some plants might rely on soil less than others/grow at a slower or faster pace.
Answer:
The correct answer is C. In the plaque assay for bacteriophages, the plaque is a clear zone caused by a zone of lysis.
Explanation:
The plaque assay is an approach used for titering bacteriophage stocks or determining the quantity of infectious virus in a sample. Plaques are visualized if you spot the phage on a lawn of growing compatible bacteria. Each plaque indicates an initial infection with one phage followed by lysis of neighboring bacteria in the lawn. Only viruses that cause visible damage of cells can be assayed in this way. The plaque assay is used to determine viral titer as plaque-forming units per ml so that known amounts of virus can be used to infect cells during subsequent work.
In the plaque assay for bacteriophages, the plaque is a clear zone caused by a zone of lysis.
I think the answer is A Explanation- :)